Many therapies have been explored for the treatment of allodynia, hyperalgesia, spontaneous pain and phantom pain with varying degree of success, including non-steroidal anti-inflammatory drugs (NSAIDs), opioids, anticonvulsants, anti-arrhythmics, tricyclic antidepressants and topical agents. Alternative approaches include anaesthetic blocks, epidural administration of steroids and neurosurgical lesions. However, all of the present therapies have modest efficacy in most patients and are palliative rather than curative and their side effects represent significant limitations.
Hence, there is a high unmet need for therapies that treat allodynia, hyperalgesia, spontaneous pain and phantom pain effectively, preferably with only minor side effects not affecting the general health of the patients.
A polypeptide with the sequence of the neurotrophic growth factor Cometin has been described previously in WO 93/22437 (Innogenetics). It is suggested that the protein or its antagonist can be used as antitumor compounds, or anti-inflammatory compounds or as growth activators of T-cells and B-cells, as bone repair compounds as inducer of immunosuppressive cells, as inhibitors of anti-colony stimulating factor; or as trypanocidal agents.
WO 01/039786 (Innogenetics) discloses specific uses of polypeptides denominated as suppressive macrophage activation factors (SMAF's) wherein SMAF-1 is 100% identical to Cometin. Specifically, it is disclosed that SMAF-1 and/or SMAF-2 modulate the production of Th1, Th2 and/or Th3 cytokines and indicates how SMAF-1 molecules can be used to treat diseases mediated by type 1, type 2 and/or type 3 responses such as inflammation, infections, allergies, autoimmune diseases, transplant rejections, graft-versus-host disease, malignancies and diseases involving mucosal immunity.
WO 2010/009732 (NsGene) describes Cometin (under the name Meteorin-like or METRNL) as a neurotrophic growth factor with effects on neurrite outgrowth in dorsal root ganglion explants, on neurblast migration in subventricular zone explants and with effects in an animal model of hearing loss.